Timing nozzle for diesel engine



Nov. 26, 1968 J. H. RUSH ET AL TIMING NOZZLE FOR DIESEL ENGINE Filed June 27, 1966 ,l fA/ 40W 152 /nzors.' UZ?. Eug/zz,

TDC

efo

56 I I Sie? f.- "Q 0,

United States Patent O 3,412,602 TIMING NOZZLE FOR DIESEL ENGINE loseph H. Rush, Oak Brook, and Richard G. Marek, Carpentersville, Ill., assignors to International Harvester Company, Chicago, lll., a corporation of Delaware Filed June 27, 1966, Ser. No. 560,687 20 Claims. (Cl. 73-119) ABSTRACT OF THE DISCLOSURE Timing nozzle for a diesel engine, having an internally located Hall effect plate therein, which plate is electromagnetically sensitive to all movement of the nozzle fuel valve as it opens and closes in the nozzle, and .fthe output of which plate is applied by an electronic instrument to appropriate utilization means such as a stroboscope timing lamp.

This application relates to a timing nozzle for a diesel engine. It particularly relates to such a nozzle having a nozzle valve, and having associated noncontact, output means which senses the cyclic time of opening and duration of opening of that valve so that fuel injection apparatus provided on the engine can be set to inject with the characteristics desired.

Prior devices of the general type proposed for timing diesel engines have employed, as one example, a mechanical connection to the nozzle valve. The resultant moving mass is obviously larger than the mass of the valve alone. Another example is a device having an hydraulic connection.

The problem is that dynamic displacement measurement is difficult with prior devices, the general type of which introduce an added factor of further inertia which compared to the results from regular nozzles, creates somewhat distorted results due to lag time. The mentioned hydraulic connection type introduces hydraulic lead or lag time, depending upon where the connection is made.

Our invention, which operates strictly on a noncontact, electrical pickup basis and which does not display any measurable phase shift or consequent lead or lag, rnaterially reduces or substantially eliminates the foregoing difiiculties, as will now be explained. Various features objects, and advantages will either be specifically pointed out or become apparent when, for a better understanding of the invention, reference is made to the following written description, taken in conjunction with the accompanying drawings which show a preferred embodiment thereof, and in which:

FIGURE l is a transverse sectional view, in schematic form, of a diesel engine embodying the invention;

FIGURE 2 is a fragmentary enlarged view of a detail of FIGURE l;

FIGURE 3 is a schematic view of the interrelationships between the mechanical and electrical components of FIGURE l, and

FIGURE 4 illustrates an oscillogram produced by the invention.

More particularly in the drawing, the No. 1 cylinder of a diesel engine is shown having a timing nozzle 12 positioned in the customary location for the standard nozzle, not shown, in the head of the cylinder. The nozzle 12 is valve controlled by an hydraulically operated valve needle 14 therein. The valve needle 14 unseats at the time that a reciprocating piston 16 appr-caches its top dead center position during the compression stroke ofthe cycle, causing the nozzle to spray jets of fuel into a combustion chamber 18. The other strokes follow in the regular order of expansion, exhaust, and suction.

A sensor or pickup plate 20 in the nozzle 12 is elec- 3,412,602 Patented Nov. 26, 1968 ICC trically coupled to a stroboscope lamp 22 by the first branch of a circuit including a selector switch 24 and a pulse conditioner 26. A second bnanch 28 of t-he circuit includes appropriate amplifiers and an oscilloscope 30 having an induction pickup head 32.

Adjacent a fixed pointer 34 on the engine, there -are a set of moving timing indicia 36 and a moving slug 38 which are on a common engine part driven by a pistonoonnected, engine crankshaft 40.

The electrical arrangement is such that, when the selector switch 24 occupies the position closing the first branch. the pickup plate Z0 causes tthe lamp 22 to flash, illuminating the indicia 36 at the instant at which the valve needle 14 commences opening during each fuel spraying cycle. When the selector switch 24 occupies the position closing the second branch 28, the oscilloscope 30 displays an oscillograph trace showing the start and duration of injection measured in terms of the valve position.

By timing indicia, We mean degree markings carried by the vibration dampener, flywheel, or other crankshaftconnected part of the engine, and coacting with the fixed pointer 34 to indicate the No. l piston position in terms of crankshaft degrees before, at, and after the piston top dead center position. By slug, We mean magnets or a magnet mounted on or in a part such as the same part indicated at 42 carrying the timing indicia, and referenced to the degree markings so that the passing field of the magnet will be picked up by the pickup head 32 'and dashed as crankshaft degree pips on the oscilloscope to provide a frame of reference for the oscillograph trace. The particular slug carrying and indicia carrying part 42 illustrated is the engine ywheel, which is a ferrous metal structure. It is appreciated that a protrusion on the flywheel or a groove therein at 38 can equally advantageously be sensed by a coil-an-d-magnet pickup to provide the desired reference pip or pips on the oscilloscope.

The pickup plate 20 needed for our purposes has characteristics which we would ideally describe as being free from imposing inertia load on the inaccessible valve needle 14, free from velocity sensitivity, free from intro'- ducing lead or lag, i.e., phase shift, free of bulk such as would have ra large space requirement, and preferably being electrical so as to have instantaneous speed of response. We have found that a Hall generator plate generally answers to that description.

More specifically, the plate 20 is flat, thin, and fits in the relieved interface between a fiat 44 machined at one side of an annular nozzle spring retainer 46, and a surrounding nozzle sleeve 48. In the prefered form a coat provided on the plate is in the shape of a cross, and is a semiconductor material.

A magnetized lower spring seat 50, which is displaced conjointly with the needle 14 along the longitudinal axis of the nozzle, provides a field which as viewed in FIG- URE 2 arches downwardly from one pole of the seat 50 back to the top pole of the seat 50. 'Ihe equatorial plane of the field is generally indicated at 52 and the particular lines of flux indicated at 54 follow a path linking the seat 50 and the plate 20.

The plate 20 has a coat as described to produce the Hall effect, involving a current flow produced in the longitudinal direction by a constant current source 56, and also involving the fiux 54 of constant strength directed into the plane of the plate 20. The current and voltage tap leads from the plate 20 are indicated at 59.

The effect is that a voltage develops across t'he plate 20, between the opposite longitudinal edges 58 and in the plane of the plate, so as to be at right angles both to current fiow and to the flux. It is a voltage of finite valve E0, and valve displacements as small as 0.001 inch are preceptible upon the oscilloscope 30 when the voltage varies with shift of the flux.

The nozzle 12 is otherwise conventional, with the further exception of the materials employed, and includes a laterally offset supply passage arm 60, a high pressure fuel supply line leading therefrom to the base of the valve needle 14 including a `longitudinal passage 62 in the wall of the spring retainer 46, and an upper spring seat 64 by which a valve seating spring 66 is fixed at one end in the nozzle 12. The valve spring 66 presses at the opposite end against the needle 14 through the interposed lower spring seat 50.

The plate 20 is bonded to the flat 44 in a fixed location so that the locus of the moving magnetized seat 50 is confined to one end of the plate 20. Therefore, the equatorial plane 52 of the magnetic field never reaches the transverse centerline of the plate 20, and E never reaches the maximum voltage possible. As a matter of fact, valve displacement is preferably small compared to the overall range possible with the plate 20, in order to insure linearity of E0 throughout the displacement.

A displacement-rotation trace is represented by FIG- URE 4, with a retrace superimposed thereon. The orthogonal axes are labeled E0 and Time, and the valve position is shown throughout each of the injections. Both t'he start of the injection and its duration are accurately read therefrom.

Following is an example of one physically constructed embodiment of the invention:

Coat on plate 20 .Indium antimonide lm. Spring seat 50 Magnetized alnico steel. Retainer 46 -..Stainless steel.

Valve needle 14 .Steel.

The diamagnetic character of the other parts does not divert the field or appreciably distort it, and so the permeable parts carry and direct the flux 54 in the desired way to the plate 20. Rising of the field due to upward movement of the magnetized seat 50 increases the Lorentz force and causes the voltage E0 to rise, and vice versa. The voltage taps in the longitudinal edges 58 of the plate are made at the middle of the plate to the indium antimonide film.

In the application of our invention to a diesel engine, the timing nozzle 12 is the only different nozzle and is installed on cylinder No. l, whereas the nozzles on the other cylinders are standard injection nozzles. It is assumed that the apparatus is precalibrated and t'he relation between nozzle actual lift and crankshaft degrees lhas been referenced to the indicia 36 and to the grid of the oscilloscope 30. Calibration is accomplished statically, and accurately so because there is no velocity sensitivity in the apparatus. Hence, when the apparatus is operated dynamically no errors are introduced.

As herein disclosed, the field is self contained within the nozzle 12, the magnetized seat 50 being in a low pressure fuel area within the retainer 46 and the plate 20 being in a low pressure fuel area between the sleeve 48 and retainer 46. On the other hand, it is evident that the seat 50 can be made of unmagnetized paramagnetic material and that the plate 20 and a fixed magnet will afford' displacement readings if externally mounted on opposite sides of the nozzle 12. That is, the distortion of the linking ux eld due to movement of the paramagnetic seat will likewise vary the trace on the oscilloscope and hence the output from the plate can be employed for operating a strobe lamp or oscilloscope. Self evidently, these principles equally apply to other inaccessible moving parts within mechanisms, whose displacement can thus be accurately measured.

The engine receives its fuel from a conventional fuel metering pump 68. The drain return passage from the low pressure areas within the particular nozzle 12 is indicated at 67. A variable pump drive 70 drivingly connects the engine 10 and the pump 68, allowing the pump timing port, not shown, and the pump metering port, not

shown, to be varied in their angular relation in the pump 68 so as to control the injection advance and load setting for the engine.

By setting the selector switch 24, the strobe lamp 22 is first employed, and used as the basis for timing start of the injection e.g., l() degrees BT DC. Thereafter, a switchover is made to the oscilloscope 30 for determining injection duration, as by reference to the trace on the oscillogram (FIGURE 4).

Once the time and duration are properly set by means of the drive 70, the nozzle 12 is removed. A standard nozzle is substituted in its place and the engine is placed back in regular service.

What is claimed is:

1. A fuel injection nozzle for use in timing apparatus for a diesel engine, including:

a sleeve;

displaceable nozzle valve structure therein, having its movement generally along a longitudinal axis and defining internally of said structure a valve-seating spring chambers;

sensor structure adjacent said sleeve and spring chamber, in a transversely offset location relative to the axis of movement of the valve structure; and

means providing a field through the nozzle magnetically interlocking the valve and sensor structures.

2. The invention of claim 1, characterized by said sensor structure comprising a Hall generator plate.

3. The invention of claim 2, characterized by said field providing means lcomprising a magnetized metal part of the valve structure substantially transversely aligned with the Hall generator plate.

4. The invention of claim 3, wherein the location of the magnetized metal part is characteristically nearer one end than the other end of the Hall generator plate, so that the equatorial plane of the magnetic eld of said part never reaches a point of precise transverse alignment with the middle of the plate.

5. A fuel injection nozzle for use in timing apparatus for a diesel engine, including:

a sleeve;

displaceable nozzle valve structure therein, having its movement generally along a longitudinal axis;

sensor structure adjacent said sleeve in a transversely offset location relative to the axis of movement of the valve structure;

a magnetized metal valve part providing a eld through the nozzle magnetically interlocking the valve and sensor structures;

a valve spring arranged within the sleeve and with an annular space therebetween;

an annular spring retainer in said space and around the spring;

a valve needle projecting at an inner end thereof into the retainer; and

a valve spring seat between and engaging the spring and said inner end of the needle, and constituting the magnetized metal part aforesaid so as to shift the field provided thereby as the valve structure is displaced.

6. The invention of claim 5, said nozzle characterized by further including:

a high pressure fuel path, and low pressure fuel areas, said Hall generator plate being in a low pressure fuel area.

7. The invention of claim 6, further characterized by:

said sleeve and said retainer having low pressure fuel areas therewithin;

the wall of said retainer having a generally longitudinally 'extending passage therein forming part of the high pressure fuel path.

8. Timing apparatus for a diesel engine having timing indicia on a moving part thereof, said apparatus comprising a fuel injection nozzle having:

a sleeve;

nozzle valve structure therein displaceable in opening and closing generally along a longitudinal axis and defining internally of said structure a valveseating spring chamber;

sensor structure which is in said sleeve, adjacent said spring chamber, and in a transversely offset location relative to the axis of displacement of the valve structure; and

means providing within the nozzle a self-contained field to interlock the two structures, enabling non-contact operation of the sensor structure to detect longitudinal displacement of the valve structure.

9. The invention of claim 8, characterized by said self contained field being an interlocking magnetic field.

10. The invention of claim 8, characterized by said sensor structure comprising a Hall generator plate:

said field providing means comprising a magnetized metal part of the valve structure substantially transversely aligned with the Hall generator plate. 11. The invention of claim 10, wherein the location of the magnetized metal part is characteristically nearer one end than the other end of the Hall generator plate, so that the equatorial plane of the magnetic field of said part never reaches a point of precise transverse alignment with the middle of the plate.

12. Timing apparatus for a diesel engine having timing indicia on a moving part thereof, said apparatus comprising a fuel injection nozzle having:

a sleeve; nozzle valve structure therein displaceable in opening and closing generally along a longitudinal axis;

sensor structure in said sleeve in a transversely offset location relative to the axis of displacement of the valve structure;

means providing within the nozzle a self-contained field to interlock the two structures, enabling non-contact operation of the sensor structure to detect longitudinal displacement of the valve structure;

said sensor structure comprising a Hall generator plate,

and said field providing means comprising a magnetized metal part of the valve structure substantially transversely aligned with the Hall generator plate;

a valve spring within the sleeve and together arranged with an annular space therebetween;

an annular spring retainer arranged with the wall thereof about the spring, and in said space;

a valve needle projecting at one end into the retainer;

and

a valve spring seat in the retainer between and engaging the spring and needle, and constituting the magnetized metal part aforesaid so as to shift the field provided thereby as the valve structure opens and closes.

13. The invention of claim 12, Said nozzle being further characterized by having:

a high pressure fuel path; and

lo'w pressure fuel areas, said Hall generator plate being in a low pressure fuel area.

14. The invention of claim 13, further characterized by:

said sleeve and retainer having low pressure fuel areas therewithin;

the wall of said retainer having a generally longitudinally extending passage therein forming part of the high pressure fuel path.

15. The invention of claim 14, said apparatus being further characterized by:

a signal lamp for illuminating the timing indicia aforesaid on the moving part of the engine; and

circuit means coupled by coupling means in the output of the Hall generator plate and having a connection to light said lamp upon initial opening of said valve structure.

16. The invention of claim 15, said circuit means characterized by a first branch including said lamp connection and a second branch:

said second branch including oscilloscope means providing a visible trace of the timing and duration characteristics of injection.

17. The invention of claim 16, said coupling means being characterized by a selector switch to selectively connect the first branch or the second branch in said circuit means.

18. The invention of claim 16, said second branch of the circuit means being characterized by a magnetic signal pickup coupling the moving part of said engine and the oscilloscope means for providing crankshaft reference marks on said visible trace.

19. The invention of claim 12, characterized 'by said 'I- spring seat being magnctized, there being other parts of the valve structure of nonmagnetic metal including, but not limited to, said annular spring retainer.

20. The invention of claim 19, the parts of said nozzle valve structure being characterized by a stainless steel retainer and a spring of nonmagnetic metal.

References Cited UNITED STATES PATENTS 3,260,117 7/1966 Rush. 3,289,077 1l/l966 Miller. 3,344,663 10/1967 Dreisin et al. 73-119 RICHARD C. QUEISSER, Primary Examiner.

JERRY W. MYRACLE, Assistant Examiner. 

